minidlna: Add media directory selection form

The form provides an option to select default directory, user specified
directory or samba shares if enabled.

The form also checks that the directory exists and is readable by the
minidlna user.

Tested that changing media directory to a samba share location works.

Closes #2084.

Signed-off-by: Veiko Aasa <veiko17@disroot.org>
Reviewed-by: Sunil Mohan Adapa <sunil@medhas.org>

plinth/modules/minidlna/__init__.py

@@ -29,6 +29,8 @@ _description = [
       'such as PS3 and Xbox 360) or applications such as totem and Kodi.')
 ]
 
+SYSTEM_USER = 'minidlna'
+
 
 class MiniDLNAApp(app_module.App):
     """Freedombox app managing miniDlna."""

plinth/modules/minidlna/forms.py

@@ -3,20 +3,21 @@
 FreedomBox configuration form for MiniDLNA server.
 """
 
-from django import forms
 from django.utils.translation import gettext_lazy as _
 
+from plinth.modules.storage.forms import (DirectorySelectForm,
+                                          DirectoryValidator)
 
-class MiniDLNAServerForm(forms.Form):
+from . import SYSTEM_USER
+
+
+class MiniDLNAServerForm(DirectorySelectForm):
     """MiniDLNA server configuration form."""
-    media_dir = forms.CharField(
-        label=_('Media Files Directory'),
-        help_text=_('Directory that MiniDLNA Server will read for content. All'
-                    ' sub-directories of this will be also scanned for media '
-                    'files. '
-                    'If you change the default ensure that the new directory '
-                    'exists and that is readable from the "minidlna" user. '
-                    'Any user media directories ("/home/username/") will '
-                    'usually work.'),
-        required=False,
-    )
+
+    def __init__(self, *args, **kw):
+        validator = DirectoryValidator(username=SYSTEM_USER)
+        super().__init__(
+            title=_('Media Files Directory'), help_text=_(
+                'Directory that MiniDLNA Server will read for content. All '
+                'sub-directories of this will be also scanned for media files.'
+            ), default='/var/lib/minidlna', validator=validator, *args, **kw)

plinth/modules/minidlna/views.py

@@ -1,8 +1,6 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
 """Views for the minidlna module."""
 
-import os
-
 from django.contrib import messages
 from django.utils.translation import gettext_lazy as _
 
@@ -21,7 +19,8 @@ class MiniDLNAAppView(AppView):
     def get_initial(self):
         """Return initial values of the form."""
         initial = super().get_initial()
-        initial.update({'media_dir': privileged.get_media_dir()})
+        initial.update({'storage_path': privileged.get_media_dir()})
+
         return initial
 
     def form_valid(self, form):
@@ -29,12 +28,8 @@ class MiniDLNAAppView(AppView):
         old_config = form.initial
         new_config = form.cleaned_data
 
-        if old_config['media_dir'].strip() != new_config['media_dir']:
-            if os.path.isdir(new_config['media_dir']) is False:
-                messages.error(self.request,
-                               _('Specified directory does not exist.'))
-            else:
-                privileged.set_media_dir(new_config['media_dir'])
-                messages.success(self.request, _('Updated media directory'))
+        if old_config['storage_path'] != new_config['storage_path']:
+            privileged.set_media_dir(new_config['storage_path'])
+            messages.success(self.request, _('Updated media directory'))
 
         return super().form_valid(form)